Rat hole drill



Jan. 8, 1952 Filed Aug. 24, 1948 Fig.

R. E. CRAINE, 5R

RAT HOLE DRILL 2 SHEETS-SHEET l Robert E. Craine, Sr.

INVENTOR.

BY 2mm Jan. 8, 1952 R. E. CRAINE, SR

RAT H0122: DRILL 2 SHEETS-SHEET 2 Filed Aug. 24, 1948 INVENTOR.

N MN

Robert E. Cra/ne, 5/.

BY w

Patented Jan. 8, 1952 UNITED STATES PATENT OFFICE 2,581,362 RAT HOLE DRILL Robert E. Craine, Sn, Great Bend, Kane.

Application August24, 1948, Serial N 0. 45,906. a claims. (01. 255-23) This invention relates to a rat hole drilling mechanism for rotary oil well drilling rigs which include a rotary table adapted to rotate the Kelly rod or joint of a drilling string while itis suspended from a derrick.

It is customary practice, preparatory to drilling a well, to drill a slanting rat hole beside the well site to accommodate the Kelly rod or joint while the drilling string is being withdrawn from or run into the well, or when additional joints of pipe are to be added to the string.

The primary object of the present invention is to provide a novel portable rat hole drilling mechanism including a hubbed driven sprocket wheel adapted to receive and drive the Kelly rod, a driving sprocket wheel adapted to be received in and driven by the master turn table bushing of arotary drilling rig and to be operatively connected to the driven sprocket wheel by means of a sprocket chain, and a pivoted support and bearing for said driven sprocket wheel which is adjustably tiltable about a horizontal axis to accommodate the Kelly rod in the desired slanting position.

Another object is to provide novel means to mount the support and bearing for the driven sprocket wheel so as to provide for easy and quick vertical rectilinear and lateral tilting adjustment thereof, whereby to obtain the best relation of said driven sprocketwheel to the driving sprocket wheel and the desired slanting position of the Kelly rod.

The exact nature of the present invention will become apparent from the following description when considered in connection with the accompanying drawings, in which:

Figure 1 is a fragmentary side. elevational view ofa drilling rig equipped with a rat hole drilling mechanism embodying the present invention;

Figure 2 is an enlarged fragmentary view, partly in side elevation and partly in section, showing the rotary of the drilling rig and the present mechanism operatively associated therewith;

Figure 3 is a top plan view of the construction shown in Figure 2;

Figure 4 is an enlarged vertical section taken on line 4-4 of Figure 3, with the sprocket chain omitted;

Figure 5 is a transverse vertical section taken on line 5-5 of Figure 4;

Figure 6 is a vertical section taken on line 8-6 of Figure 5;

Figures '7 and 8 are horizontal sectional views respectively taken on line 1-1 and line 8-8 of Figure 6;

Figure 9 is an enlarged. side elevational view of the driving sprocket.

Referring in detail to the drawings, 5 indicates the derrick of a rotary drilling rig having a bottom platform 6 and a hoisting tackle 1 for supporting the Kelly rod 8 and any drill pipe connected' therewith, the tackle including a block 5 connected to'the swivel head ID of the Kelly rod. The drilling rig includes a main rotary H carried by the platform 61 and embodying aturntable l2 geared to the drive shaft E3 of a motor it. The turntable i2 is provided with the usual bushing l5 adapted to receive an ordinary Kelly rod drive bushing, not shown. The master bushing has a central non-circular recess it at the top thereof, in which the drive bushing is adapted to be seated so as to be turned with said master bushing.

The present invention includes a driving sprocket wheel 11 having a rigid central depending stem [8 provided intermediate its, ends with a rigid polygonal plate l9 adapted to seat in the recess IQ of the master bushing, upon removal of the Kelly drive bushing, so as to provide a driving connection between the master bushing l5 and the sprocket wheel I? and to support the latter in spaced relation to and. above the turntable.

Mounted on the platform 6 a short distance from the main rotary H is a rat hole rotary 20 which includes a horizontal base frame 2! composed of spaced parallel beams 22 rigidly connected near their ends by crossbeams 23. The rotary 251 also includes a pair of spaced parallel plate uprights 24 rigidly secured upon the beams 22 and each. having a central vertical elongated slot 25 and a vertical series of uniformly spaced apertures 26 at each side of said slot. A hearing and support for a hubbed driven sprocket wheel 21 is arranged, between the uprights 24, and it includes a cylindrical sleeve 23 provided at. opposite sides and intermediate its ends with laterally projecting co-axial, spindles 29 projecting into and 'freely movable in the slots 25 of the uprights. -The spindles 29 rotatably rest in bearing notches 30 provided in the upper edges of bearing plates 3! mounted on the outer sides of uprights 24 for vertical adjustment, so as to adjust the height of the sprocket wheel 21. As shown, the plates 3| have vertical elongated slots 32, and bolts 33 pass through these slots and screw into the uprights to secure said plates 3| in adjusted positions. The sprocket wheel 21 rests on the upper end of sleeve 28 and has a, large cylindrical hub 34 journaled 1n sleeve 28 by means of bearings 35.

' 3 Thus, the sleeve 28 and sprocket wheel 21 are mounted for lateral tilting movement about the horizontal axis defined by spindles 29. Means is provided to secure the sleeve 28 and sprocket 21 in different tilted positions, such means preferably including disks 36 fixed on the spindles 29 at the inner sides of uprights 24 and each having two arculate series of apertures 31 concentric with such spindles and selectively registrable with certain of the apertures of the uprights 24 according to the height at which the sleeve 28 is adjusted, and nutted bolts 38 passing through the registered apertures 26 and 31. The sprocket wheel 21' and its hub 34 are diametrically split, and the two sections or halves are secured together by arcuate plates 39 which are bolted at 40 on said sprocket wheel and which span the joints between the sections thereof. Hub 34 has a square bore 41 to snugly receive the Kelly rod so as to drive the latter, and the sections of wheel 21 and its hub 34 may be separated to place them on the Kelly rod. A sprocket chain 42 is passed around the sprocket wheels I! and 27 to provide a driving connection therebetween.

To drill a rat hole, a rotary bit 44 is attached to the Kelly rod, and the latter is passed through the sleeve 28. The hubbed sprocket wheel 21 is then assembled to the Kelly rod and lowered into the sleeve 28, the latter having been adjusted to the desired height and inclination or tilted position. The sprocket wheel I! is then assembled to the master bushing 15 after removal of the Kelly drive bushing therefrom, whereupon the chain 42 is placed around the wheels I! and 21'. The motor :4 is then thrown into operation to drive the turntable l2 and wheel 11, and motion is transmitted from the latter to the Kelly rod through chain 42 and wheel 2?, to drill the rat hole.

From the foregoing description, it is believed that the construction, operation and advantages of the present invention will be readily understood and appreciated by those skilled in the art. Modifications and changes in details of construction are contemplated, such as fairly fall within the spirit and scope of the invention as claimed.

Having described the invention, what is claimed as new is:

1. In a rat hole drilling mechanism, a rat hole rotary comprising a base having spaced uprights, a sleeve arranged between and pivotally and slidably mounted in said uprights for lateral tilting adjustment about a horizontal axis and for rectilinear vertical adjustment, and a hubbed sprocket wheel resting on the upper end of said sleeve and having its hub journaled in said sleeve and adapted to receive and turn 9. Kelly rod, said sprocket wheel adapted to have a sprocket chain passed around the same to transmit motion thereto from a drive sprocket wheel assembled to the master bushing in the turntable of the main rotary of an oil well drilling rig, said hubbed sprocket wheel being split diametrically into two halves, and arcuate plates disposed on and bolted on the top of said hubbed sprocket wheel to join the halves thereof.

2. In a rat hole drilling mechanism, a rat hole rotary comprising a base having spaced uprights, a sleeve arranged between and pivotally and slidably mounted in said uprights for lateral tilting adjustment about a horizontal axis and for rectilinear vertical adjustment, and a hubbed sprocket wheel resting on the upper end of said sleeve and having its hub journaled in said sleeve and adapted to receive and turn a Kelly rod, said sprocket wheel adapted to have a sprocket chain passed around the same to transmit motion thereto from a drive sprocket wheel assembled to the master bushing in the turntable of the main rotary of an oil well drilling rig, said uprights having central vertical elongated slots therein, coaxial spindles rigid with said sleeve and freely projecting into said slots, and vertically adjustable bearing plates mounted on the outer sides of said uprights and rotatably supporting said spindles,

3. In a rat hole drilling mechanism, a rat hole rotary comprising a base having spaced uprights, a sleeve arranged between and pivotally and slidably mounted in said uprights for lateral tiltin adjustment about a horizontal axis and for rectilinear vertical adjustment, and a hubbed sprocket wheel resting on the upper end of said sleeve and having its hub journaled in said sleeve and adapted to receive and turn a Kelly rod, said sprocket Wheel adapted to have a sprocket chain passed around the same to transmit motion thereto from a drive sprocket wheel assembled to the master bushing in the turntable of the main rotary of an oil well drilling rig, said uprights having vertical series of apertures therein, apertured disks fixed on said spindles at the inner sides of said uprights, and bolts passing through registered apertures of the uprights and disks and adapted to secure the sleeve in tiltably adjusted position in any vertically adjusted position thereof.

ROBERT E. CRAINE, Sn.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Brown NOV. 12, 1946 

